Method for large hydrogen liquefaction system

ABSTRACT

A method for the liquefaction of hydrogen is provided. The can include the steps of: precooling a hydrogen feed stream in a precooling cold box having a heat exchanger disposed therein to form a cooled hydrogen stream, wherein the heat exchanger is configured to cool down the feed stream within the precooling cold box by indirect heat exchange between the hydrogen feed stream and a precooling refrigerant; and withdrawing the cooled hydrogen stream from the precooling cold box; introducing the cooled hydrogen stream to a plurality of liquefaction cold boxes, wherein the cooled hydrogen stream liquefies within the plurality of liquefaction cold boxes by indirect heat exchange against a liquefaction refrigerant to form a product hydrogen stream in each of the plurality of liquefaction cold boxes, wherein the product hydrogen stream is in liquid form or pseudo-liquid form wherein there are M total precooling cold boxes and N total liquefaction cold boxes, wherein M is less than N.

CROSS REFERENCE OF RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 63/104,806 filed on Oct. 23, 2021, and U.S. Provisional ApplicationSer. No. 63,293,080 filed on Dec. 22, 2021, both of which are herebyincorporated by reference in their entireties.

TECHNICAL FIELD

The present invention generally relates to a method and apparatus forproducing liquid hydrogen, particularly in large quantities.

BACKGROUND OF THE INVENTION

Hydrogen is a key molecule as a sustainable energy carrier. Liquefactionof hydrogen is key for its transportation and distribution to localmarkets.

Hydrogen liquefaction processes require refrigeration over a very widetemperature range (20K to 300K). It is common to have separate dedicatedrefrigeration systems for the warm end (80K to 300K) and the cold end(20K to 80K) since the specific refrigeration demands and cost varysignificantly with temperature. Regarding the warm temperature range(80K to 300K): referenced art exists using a) closed loop N₂ cycle, b)vaporization of LIN from an ASU, c) mixed hydrocarbon refrigerant, andd) optionally pre-precooling to a first temperature (250K to 300K) usingNH₃ and/or water. Regarding the cold temperature range (20K to 80K):referenced art exists using closed loop H₂ cycle, He cycle, and/or Ne/Hecycles.

It is known in the art that the largest equipment within the cold boxesare the heat exchangers (typically brazed aluminum). As shown in TableI, the required heat exchanger surface area (which is directly relatedto UA i.e., heat transfer coefficient x area) significantly decreases atcolder temperatures. As a result, typical good engineering practicewould be to design multiple modules split by temperature level (anddifferent insulation types) and for each level of temperature to designmultiple parallel trains according to heat exchange surface areas.Therefore, normal engineering work will consist of M precooling coldboxes and N liquefaction cold boxes with M>N. In the Table below, MR ismixed refrigerant, N2 is nitrogen, He is helium, Ne is neon, and H2 ishydrogen.

TABLE I Heat Exchanger Surface Area as a Function of Refrigerant Type

Cold end refrigeration (20K to 80K) is achieved by turbo-expansionand/or isenthalpic expansion and/or vaporization of light gases such asH₂, He, Ne, etc . . . . The primary refrigeration is fromturbo-expansion due to its high efficiency; however, this equipment islimited in capacity due to the technology of expansion of low molecularweight gases. This is typically partially offset by use of multipleexpanders in series or parallel (e.g., 2×50%, 3×33%, etc . . . ).However, in the case of hydrogen liquefaction equipment, the limitingcapacity constraint of the low molecular weight turbine is on the orderto 10 to 30 times less than the limiting capacity constraint of othermajor process equipment.

A typical hydrogen liquefaction process may include a precooling sectionconsisting of dual N₂ expanders (1 warm and 1 cold N₂ expanders) andcooling/liquefaction section consisting of H₂ or He expanders. In thisexample, if one designs the LH₂ liquefaction capacity for maximumutilization of the single warm and cold N₂ turbine frames, then theresulting number of H₂ or He turbine units is in the order of 10.

Therefore, there is a need for a process and apparatus for anarrangement, which allows for utilization of the larger capacitiespossible of other equipment.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a device and a method and apparatusthat satisfies at least one of these needs.

A hydrogen liquefaction apparatus comprising a precooling zone and acooling/liquefaction zone. The precooling zone, which comprises aplurality a precooling units, cools a H₂ feed stream to a firstintermediate temperature followed by cooling/liquefaction in thecooling/liquefaction zone. The cooling/liquefaction zone comprises Nunits such that each unit receives at least a portion of the hydrogenstream, which is split from the precooling zone, wherein the number ofPrecooling units is less than N. This is surprising and contrary to theconventional wisdom as discussed, supra, and shown in Table I.

In a first embodiment, the intermediate temperature is in the range of70K to 300K, and preferably in the range of 70K to 100K. In oneembodiment, the precooling zone cools the H₂ stream with a refrigerantcomprising one or more of ammonia, mixed hydrocarbons, nitrogen or otherknow refrigerant.

In another embodiment, the cooling/liquefaction zone cools the H₂ steamwith a refrigerant comprising one or more of hydrogen, helium, neon.

In another embodiment, there is an intermediate cooling zone where thehydrogen stream is cooled to a second intermediate temperature. Wherethe number of units of the warm section is less than number of units ofthe colder section. In optional embodiments, it is possible to includemultiple levels of cooling, e.g., (1) water, (2) NH₃ refrigerant, (3)mixed hydrocarbon refrigerant, (4) N₂ refrigerant, and (5) H₂ and/or Herefrigerant.

In another embodiment, at least a portion of the low-pressurerefrigerant stream(s) received from the cooling/liquefaction units issent to a refrigerant precooling unit. At least a portion of the HPrefrigerant stream is cooled against lower pressure return refrigerantstream(s).

In one embodiment, a hydrogen liquefaction apparatus can include: aprecooling cold box having a heat exchanger disposed therein, whereinthe heat exchanger is configured to cool down a feed stream within theprecooling cold box by indirect heat exchange between the feed streamand a precooling refrigerant; a plurality of liquefaction cold boxes influid communication with the precooling cold box, wherein eachliquefaction cold box comprises its own heat exchanger, wherein eachheat exchanger within the plurality of liquefaction cold boxes isconfigured to liquefy the feed stream by indirect heat exchange with aliquefaction refrigerant; a precooling refrigeration system configuredto provide refrigeration to the precooling zone; and a liquefactionrefrigeration system configured to provide the liquefaction refrigerantto the plurality of liquefaction cold boxes, wherein there are M totalprecooling cold boxes and N total liquefaction cold boxes, wherein M isless than N.

In optional embodiments of the apparatus:

the liquefaction refrigeration system comprises a recycle compressionsystem and an expansion system, wherein the recycle compression systemis configured to compress the liquefaction refrigerant and the expansionsystem is configured to expand the liquefaction refrigerant;

there are M total recycle compression systems and/or N totalliquefaction expansion systems;

the recycle compression system comprises one or more recyclecompressors;

the one or more recycle compressors are arranged in parallel and/orseries;

liquefaction expansion system comprises one or more liquefactionexpanders, wherein the one or more liquefaction expanders are arrangedin parallel and/or series;

the liquefaction refrigerant is selected from the group consisting ofhydrogen, neon, helium, and combinations thereof;

the liquefaction refrigerant comprises one or more of hydrogen, neon,and helium;

the precooling system comprises a precooling refrigeration cycle;

the precooling refrigerant is selected from the group consisting ofnitrogen, argon ammonia, carbon monoxide, carbon dioxide, water,hydrocarbon, mixed hydrocarbons, fluorocarbons, and combinationsthereof;

the precooling refrigerant comprises one or more of nitrogen, argonammonia, carbon monoxide, carbon dioxide, water, hydrocarbon, mixedhydrocarbons, and fluorocarbons;

the liquefaction refrigeration system comprises a single, common recyclecompression system;

the apparatus can further include an intermediate cold box in fluidcommunication with the precooling cold box and the plurality ofliquefaction cold boxes, wherein the intermediate cold box is disposedbetween the precooling cold box and the plurality of liquefaction coldboxes; and/or

the ratio of N total liquefaction cold boxes to M total precooling coldboxes is between 1.25 and 3.0 (1.25≤N/M≤3.0).

In another embodiment, a liquefaction apparatus can include: a firstcooling cold box configured to receive a feed stream at an initialtemperature T₀ and cool the feed stream to form a cooled feed stream ata cooled temperature T₁; a first precooling withdrawal line configuredto remove the cooled feed stream from the first cooling cold box; ameans for splitting the cooled feed stream, wherein the means forsplitting the cooled feed stream are in fluid communication with theprecooling withdrawal line, a plurality of secondary cold boxes in fluidcommunication with the means for splitting the cooled feed stream,wherein the plurality of secondary cold boxes are configured to receivethe cooled feed stream from the means for splitting the cooled feedstream and liquefy the cooled feed stream therein to form a liquefiedstream at a liquefaction temperature T_(L), wherein there are M totalfirst cooling cold boxes and N total secondary cold boxes, wherein M isless than N.

In optional embodiments of the apparatus:

each secondary cold box comprises its own heat exchanger(s), whereineach heat exchanger within the plurality of secondary cold boxes isconfigured to liquefy the cooled feed stream by indirect heat exchangewith a liquefaction refrigerant;

the apparatus can further include: a liquefaction refrigeration system,the liquefaction refrigeration system comprising a recycle compressionsystem and an expansion system, wherein the recycle compression systemis configured to compress a liquefaction refrigerant and the expansionsystem is configured to expand the liquefaction refrigerant;

the apparatus can further include: a means for combining theliquefaction refrigerant, wherein the means for combining theliquefaction refrigerant is configured to receive the liquefactionrefrigerant from a warm end of each of the plurality of secondary coldboxes via a plurality of pipes and then send the liquefactionrefrigerant, after being combined, to the first cooling cold box via afirst return line;

the apparatus can further include: a second precooling withdrawal lineconfigured to remove the liquefaction refrigeration stream from a coldend of the first cooling cold box; and/or

the apparatus can further include a means for splitting the liquefactionrefrigeration stream, wherein the means for splitting the liquefactionrefrigeration stream are in fluid communication with the secondprecooling withdrawal line.

In yet another embodiment, a method for the liquefaction of hydrogen caninclude the steps of: precooling a hydrogen feed stream in a precoolingcold box having a heat exchanger disposed therein to form a cooledhydrogen stream, wherein the heat exchanger is configured to cool downthe feed stream within the precooling cold box by indirect heat exchangebetween the hydrogen feed stream and a precooling refrigerant;withdrawing the cooled hydrogen stream from the precooling cold box; andintroducing the cooled hydrogen stream to a plurality of liquefactioncold boxes, wherein the cooled hydrogen stream liquefies within theplurality of liquefaction cold boxes by indirect heat exchange against aliquefaction refrigerant to form a product hydrogen stream in each ofthe plurality of liquefaction cold boxes, wherein the product hydrogenstream is in liquid form or pseudo-liquid form, wherein there are Mtotal precooling cold boxes and N total liquefaction cold boxes, whereinM is less than N.

In optional embodiments of the method:

the liquefaction refrigeration system comprises a recycle compressionsystem and an expansion system, wherein the recycle compression systemis configured to compress the liquefaction refrigerant and the expansionsystem is configured to expand the liquefaction refrigerant;

there are M total recycle compression systems and N total liquefactionexpansion systems;

the recycle compression system comprises one or more recyclecompressors;

the one or more recycle compressors are arranged in parallel or series;

liquefaction expansion system comprises one or more liquefactionexpanders, wherein the one or more liquefaction expanders are arrangedin parallel or series;

the liquefaction refrigerant is selected from the group consisting ofhydrogen, neon, helium, and combinations thereof;

the liquefaction refrigerant comprises one or more of hydrogen, neon,and helium;

the precooling system comprises a precooling refrigeration cycle;

the precooling refrigerant is selected from the group consisting ofnitrogen, argon, ammonia, carbon monoxide, carbon dioxide, water,hydrocarbon, mixed hydrocarbons, fluorocarbon and combinations thereof;

the precooling refrigerant comprises one or more of nitrogen, argon,ammonia, carbon monoxide, carbon dioxide, water, hydrocarbon, mixedhydrocarbons, and fluorocarbons;

the cold end refrigeration cycle comprises a single, common recyclecompression system;

the method can also include an intermediate cold box in fluidcommunication with the precooling cold box and the plurality ofliquefaction cold boxes, wherein the intermediate cold box is disposedbetween the precooling cold box and the plurality of liquefaction coldboxes;

the temperature at a cold end of the precooling cold box is in the rangeof 30K to 250K;

the temperature at a warm end of the liquefaction zone is in the rangeof 30K to 150K; and/or

the ratio of N total liquefaction cold boxes to M total precooling coldboxes is between 1.25 and 3.0 (1.25≤N/M≤3.0).

In another embodiment, the liquefaction method can include the steps of:introducing a feed stream into a pre-cooling cold box at an initialtemperature T₀ and cooling the feed stream therein to form a cooled feedstream at a cooled temperature T₁; withdrawing the cooled feed streamfrom the pre-cooling box using a first precooling withdrawal line;splitting the cooled feed stream into a first cooled feed stream and asecond cooled feed stream; providing a plurality of subcooling boxes,wherein the plurality of subcooling cold boxes comprise a firstsubcooling cold box and a second subcooling cold box; introducing thefirst cooled feed stream into the first subcooling cold box underconditions effective for subcooling the first cooled feed stream to forma first product stream at a product temperature T_(L), wherein the firstproduct stream is in liquid form or a pseudo-liquid form; introducingthe second cooled feed stream into a second subcooling cold box underconditions effective for subcooling the second cooled feed stream toform a second product stream, wherein the second product stream is inliquid form or pseudo-liquid form; withdrawing the first and secondproduct streams from the first and second subcooling cold boxes; andcombining the first and second product streams into a final productstream.

In optional embodiments of the liquefaction method:

each secondary cold box comprises its own heat exchanger, wherein eachheat exchanger within the plurality of secondary cold boxes isconfigured to liquefy the feed stream by indirect heat exchanger with aliquefaction refrigerant;

the liquefaction method can also include: a liquefaction refrigerationsystem, the liquefaction refrigeration system comprising a recyclecompression system and an expansion system, wherein the recyclecompression system is configured to compress a liquefaction refrigerantand the expansion system is configured to expand the liquefactionrefrigerant;

the liquefaction method can also include: a means for combining theliquefaction refrigerant, wherein the means for combining theliquefaction refrigerant is configured to receive the liquefactionrefrigerant from a warm end of each of the plurality of secondary coldboxes via a plurality of pipes and then send the liquefactionrefrigerant, after being combined, to the first cooling cold box via afirst return line;

the liquefaction method can also include: a second precooling withdrawalline configured to remove the liquefaction refrigeration stream from thefirst cooling cold box;

the liquefaction method can also include: a means for splitting theliquefaction refrigeration stream, wherein the means for splitting theliquefaction refrigeration stream are in fluid communication with thesecond precooling withdrawal line; and/or

the feed stream consists essentially of hydrogen.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention in order that the detaileddescription of the invention that follows may be better understood.Additional features and advantages of the invention will be describedhereinafter which form the subject of the claims of the invention. Itshould be appreciated by those skilled in the art that the conceptionand specific embodiment disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present invention.

It should also be realized by those skilled in the art that suchequivalent constructions do not depart from the spirit and scope of theinvention as set forth in the appended claims. The novel features whichare believed to be characteristic of the invention, both as to itsorganization and method of operation, together with further objects andadvantages will be better understood from the following description whenconsidered in connection with the accompanying figures. It is to beexpressly understood, however, that the figures are provided for thepurpose of illustration and description only and are not intended as adefinition of the limits of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference isnow made to the following descriptions taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a process flow diagram of an embodiment of the prior art.

FIG. 2 is an embodiment of the prior art.

FIG. 3 provides an embodiment of the present invention.

FIG. 4 provides another embodiment of the present invention.

FIG. 5 provides yet another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the invention allow for a reduction in capitalexpenditures by reducing the number of precooling zones in a hydrogenliquefaction apparatus having a plurality of cold end liquefactionzones. In certain embodiments, the hydrogen liquefaction apparatus canhave N cold-end liquefaction zones while also having less than N (e.g.,N−1, N−2, N−3, etc . . . ) precooling zones.

As shown in FIG. 1 , prior art hydrogen liquefaction units use twoidentical trains 1 a, 1 b running separately from each other. Each trainincludes a precooling zone 10 and a liquefaction zone 5. In the case ofFIG. 1 , the refrigeration for the precooling zone 10 is provided by aclosed loop refrigeration circuit 11, which is provided by compression2, 4, 6, and expansion 5, 7 of a precooling refrigerant Refrigerationfor the liquefaction zone 5 is provided by a second closed looprefrigeration circuit 13.

FIG. 2 provides a flow chart of a hydrogen liquefaction unit having fivetrains, with each train having six main sections: hydrogen compression,nitrogen compression, precooling, cooling, liquefaction, and storage.All of these identical trains would be run independently from each other(i.e., the operating conditions of each train have little to no bearingon the operating conditions of another train).

FIG. 3 , which represents an embodiment of the present invention,provides a process flow diagram showing how a hydrogen liquefactionunit, which has two liquefaction zones 20, 25, can have a singleprecooling zone 10. Refrigeration for the precooling zone 10 is providedby compression 2, 4, 6, and expansion 5, 7 of a precooling refrigerantthat is configured to cool the hydrogen feed to a first intermediatetemperature in the range of 70K to 300K, more preferably 70K to 100K.

In one embodiment, the precooling refrigerant can be ammonia, mixedhydrocarbons, nitrogen, or any other known refrigerant.

Following the precooling zone, the hydrogen feed gas is split 17,19 andsent to two separate liquefaction zones 20, 25, wherein the hydrogen iscondensed 23 a, 23 b and following removal of any non-condensed gases ingas liquid separator 39, the liquid hydrogen is ultimately sent to ahydrogen liquid storage tank 40. In certain embodiments, the hydrogencan exit the heat exchanger in pseudo-liquid form. As used herein,pseudo-liquid form may include a supercritical fluid that is anysubstance at a temperature and pressure above its critical point, wheredistinct liquid and gas phases do not exist.

In another optional embodiment, boil-off gas 42, 43 that is withdrawnfrom hydrogen liquid storage tank 40 can be rewarmed in one or bothliquefaction zones before being combined and rewarmed more in theprecooling zone 10. The warmed boil-off gas can then be compressed 50 tobecome recycled boil-off gas 52, which can be fed into the hydrogenfeed, and/or optionally, can provide make-up gas to the hydrogen recycle(not shown).

The cold end refrigerant 22, which was also cooled in the precoolingzone 10, is withdrawn from the precooling zone 10 and then split intotwo streams 12, 14, wherein the cold end refrigerant is expanded in aset of turbines (15 a, 15 b), which preferably have different incomingtemperatures, to provide cooling energy for the two liquefaction zones.After providing this cooling energy, the cold end refrigerant iswithdrawn from a warm end of the liquefaction zone 20, 25, and furtherwarmed in the precooling zone 10. After fully warming, the cold endrefrigerant is then compressed 24 again as part of its refrigerationcycle. As an optional embodiment, each of the expansion turbines of theset of turbines (15 a, 15 b) can be two or more turbines in parallel.

FIG. 4 provides an alternate embodiment in which there is again a singleprecooling zone 10 for the hydrogen feed stream. In this embodiment,however, the cold end refrigerant is not used to provide any precoolingenergy (e.g., the cold end refrigerant does not reenter the precoolingzone 10 for rewarming, but instead enters a separate heat exchanger 30to provide cooling to one portion of the cold end refrigerant). Rather,all of the precooling of the hydrogen feed stream is done by theprecooling refrigerant in the closed loop refrigeration circuit 11. Inthis way, there is a set of simple standardized modular precoolingexchanger(s) and cold box(s) and a separate set of complex customexchangers and cold box(s). The custom complex set may also comprisemost of the project specific complexities such as H₂ Feed, purification,and precooling refrigeration cycle.

The refrigeration balance between the set of simple exchangers and theset of complex exchangers is made by adjusting the flow split of HPrefrigerant between the simple and complex cores (as shown in figure)and/or by splitting one of the lower pressure refrigerant return streamsbetween the simple and complex cores. The number of simpleexchangers/cold boxes is independent of the number of complexexchangers/cold boxes. Similarly, there may be a set of modular simplestandardized liquefaction exchangers/cold boxes with integratedliquefaction refrigerant system such that the more complex, sitespecifics (such as H₂ product subcooling and boil-off return) may bemanaged in a separate customized exchanger/cold box.

As in FIG. 3 , the hydrogen feed stream is again split into two 17, 19and then further cooled and liquefied in multiple (in this embodimenttwo) liquefaction zones 20, 25. In FIG. 4 , the cold end refrigerant issplit into two streams 31, 33, with one stream 31 being first cooled inthe precooling zone 10 and the second stream 33 being cooled in a secondheat exchanger 30. This second heat exchanger does not include anycooling of the hydrogen feed stream, which thereby allows for greaterflexibility of cooling temperatures in this second heat exchanger. Forexample, the cold end refrigerant 33 in this section could be cooled toa lower temperature than the cold end refrigerant 31 in the precoolingzone. Put another way, the cold end temperature of the second heatexchanger can differ from the cold end temperature of the precoolingzone.

Following the first cooling, the two cold end refrigerant streams can bemixed together before being split into two and sent to the two separateliquefaction zones. By combining the two cold end refrigerant streamstogether, the two streams used for liquefaction the hydrogen in theliquefaction zone should have substantially similar temperatures,thereby allowing identical trains to be used, which greatly reducesengineering design and fabrication costs, thereby reducing complexity.Therefore, the embodiment shown in FIG. 4 provides an advantage of beingable to alter the temperature of the cold end refrigerant prior tointroducing it to the hydrogen liquefaction unit without thattemperature being directly tied to the hydrogen feed gas that is to beliquefied, and can provide the option for a modular (standardizedpackage) for a portion of the precooling refrigeration system.

While FIG. 4 does not show the boil-off gas recycle, those of ordinaryskill in the art will recognize that the boil-off gas recycle shown inFIG. 3 can also be used with the embodiment shown in FIG. 4 . Therefore,the lack of this element in FIG. 4 should not be interpreted to belimiting.

FIG. 5 provides a process flow chart in accordance with an embodiment ofthe present invention. As can be seen, this embodiment includes fivetrains for the liquefaction unit. Therefore, in this embodiment, N=5.However, only one train for precooling is needed. This means that theembodiment shown includes four less precooling trains than theembodiments of the prior art. Therefore, embodiments of the presentinvention are able to produce the same amount of liquid hydrogen as themethods of the prior art, while doing so with less capital expenditures.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions andalterations could be made herein without departing from the spirit andscope of the invention as defined by the appended claims. Moreover, thescope of the present application is not intended to be limited to theparticular embodiments of the process, machine, manufacture, compositionof matter, means, methods, and steps described in the specification. Asone of ordinary skill in the art will readily appreciate from thedisclosure of the present invention, processes, machines, manufacture,compositions of matter, means, methods, or steps, presently existing orlater to be developed that perform substantially the same function orachieve substantially the same result as the corresponding embodimentsdescribed herein may be utilized according to the present invention.Accordingly, the appended claims are intended to include within theirscope such processes, machines, manufacture, compositions of matter,means, methods, or steps.

The present invention may suitably comprise, consist or consistessentially of the elements disclosed and may be practiced in theabsence of an element not disclosed. Furthermore, if there is languagereferring to order, such as first and second, it should be understood inan exemplary sense and not in a limiting sense. For example, it can berecognized by those skilled in the art that certain steps can becombined into a single step or reversed in order.

The singular forms “a”, “an”, “own”, and “the” include plural referents,unless the context clearly dictates otherwise.

“Comprising” in a claim is an open transitional term which means thesubsequently identified claim elements are a nonexclusive listing (i.e.,anything else may be additionally included and remain within the scopeof “comprising”). “Comprising” as used herein may be replaced by themore limited transitional terms “consisting essentially of” and“consisting of” unless otherwise indicated herein.

“Providing” in a claim is defined to mean furnishing, supplying, makingavailable, or preparing something. The step may be performed by anyactor in the absence of express language in the claim to the contrary arange is expressed, it is to be understood that another embodiment isfrom the one.

Optional or optionally means that the subsequently described event orcircumstances may or may not occur. The description includes instanceswhere the event or circumstance occurs and instances where it does notoccur.

Ranges may be expressed herein as from about one particular value,and/or to about another particular value. When such particular valueand/or to the other particular value, along with all combinations withinsaid range.

All references identified herein are each hereby incorporated byreference into this application in their entireties, as well as for thespecific information for which each is cited.

What is claimed is:
 1. A method for the liquefaction of hydrogen, themethod comprising the steps of: precooling a hydrogen feed stream in aprecooling cold box having a heat exchanger disposed therein to form acooled hydrogen stream, wherein the heat exchanger is configured to cooldown the feed stream within the precooling cold box by indirect heatexchange between the hydrogen feed stream and a precooling refrigerant;withdrawing the cooled hydrogen stream from the precooling cold box; andintroducing the cooled hydrogen stream to a plurality of liquefactioncold boxes, wherein the cooled hydrogen stream liquefies within theplurality of liquefaction cold boxes by indirect heat exchange against aliquefaction refrigerant to form a product hydrogen stream in each ofthe plurality of liquefaction cold boxes, wherein the product hydrogenstream is in liquid form or pseudo-liquid form, wherein there are Mtotal precooling cold boxes and N total liquefaction cold boxes, whereinM is less than N.
 2. The method for the liquefaction of hydrogen asclaimed in claim 1, wherein the liquefaction refrigeration systemcomprises a recycle compression system and an expansion system, whereinthe recycle compression system is configured to compress theliquefaction refrigerant and the expansion system is configured toexpand the liquefaction refrigerant.
 3. The method for the liquefactionof hydrogen as claimed in claim 2, wherein there are M total recyclecompression systems and N total liquefaction expansion systems.
 4. Themethod for the liquefaction of hydrogen as claimed in claim 2, whereinthe recycle compression system comprises one or more recyclecompressors.
 5. The method for the liquefaction of hydrogen as claimedin claim 4, wherein the one or more recycle compressors are arranged inparallel or series.
 6. The method for the liquefaction of hydrogen asclaimed in claim 2, wherein liquefaction expansion system comprises oneor more liquefaction expanders, wherein the one or more liquefactionexpanders are arranged in parallel or series.
 7. The method for theliquefaction of hydrogen as claimed in claim 1, wherein the liquefactionrefrigerant is selected from the group consisting of hydrogen, neon,helium, and combinations thereof.
 8. The method for the liquefaction ofhydrogen as claimed in claim 1, wherein the liquefaction refrigerantcomprises one or more of hydrogen, neon, and helium.
 9. The method forthe liquefaction of hydrogen as claimed in claim 1, wherein theprecooling system comprises a precooling refrigeration cycle.
 10. Themethod for the liquefaction of hydrogen as claimed in claim 1, whereinthe precooling refrigerant is selected from the group consisting ofnitrogen, argon, ammonia, carbon monoxide, carbon dioxide, water,hydrocarbon, mixed hydrocarbons, fluorocarbon and combinations thereof.11. The method for the liquefaction of hydrogen as claimed in claim 1,wherein the precooling refrigerant comprises one or more of nitrogen,argon, ammonia, carbon monoxide, carbon dioxide, water, hydrocarbon,mixed hydrocarbons, and fluorocarbons.
 12. The method for theliquefaction of hydrogen as claimed in claim 1, wherein the cold endrefrigeration cycle comprises a single, common recycle compressionsystem.
 13. The method for the liquefaction of hydrogen as claimed inclaim 1, further comprising an intermediate cold box in fluidcommunication with the precooling cold box and the plurality ofliquefaction cold boxes, wherein the intermediate cold box is disposedbetween the precooling cold box and the plurality of liquefaction coldboxes.
 14. The method for the liquefaction of hydrogen as claimed inclaim 1, wherein the temperature at a cold end of the precooling coldbox is in the range of 30K to 250K.
 15. The method for the liquefactionof hydrogen as claimed in claim 1, wherein the temperature at a warm endof the liquefaction zone is in the range of 30K to 150K.
 16. The methodfor the liquefaction of hydrogen as claimed in claim 1, wherein theratio of N total liquefaction cold boxes to M total precooling coldboxes is between 1.25 and 3.0 (1.25≤N/M≤3.0).
 17. A liquefaction methodcomprising the steps of: introducing a feed stream into a pre-coolingcold box at an initial temperature T₀and cooling the feed stream thereinto form a cooled feed stream at a cooled temperature T₁; withdrawing thecooled feed stream from the pre-cooling box using a first precoolingwithdrawal line; splitting the cooled feed stream into a first cooledfeed stream and a second cooled feed stream; providing a plurality ofsubcooling boxes, wherein the plurality of subcooling cold boxescomprise a first subcooling cold box and a second subcooling cold boxintroducing the first cooled feed stream into the first subcooling coldbox under conditions effective for subcooling the first cooled feedstream to form a first product stream at a product temperature T_(L),wherein the first product stream is in liquid form or a pseudo-liquidform; introducing the second cooled feed stream into a second subcoolingcold box under conditions effective for subcooling the second cooledfeed stream to form a second product stream, wherein the second productstream is in liquid form or pseudo-liquid form; withdrawing the firstand second product streams from the first and second subcooling coldboxes; and combining the first and second product streams into a finalproduct stream.
 18. The liquefaction method as claimed in claim 17,wherein each secondary cold box comprises its own heat exchanger,wherein each heat exchanger within the plurality of secondary cold boxesis configured to liquefy the feed stream by indirect heat exchanger witha liquefaction refrigerant.
 19. The liquefaction method as claimed inclaim 18, further comprising a liquefaction refrigeration system, theliquefaction refrigeration system comprising a recycle compressionsystem and an expansion system, wherein the recycle compression systemis configured to compress a liquefaction refrigerant and the expansionsystem is configured to expand the liquefaction refrigerant.
 20. Theliquefaction method as claimed in claim 18, further comprising a meansfor combining the liquefaction refrigerant, wherein the means forcombining the liquefaction refrigerant is configured to receive theliquefaction refrigerant from a warm end of each of the plurality ofsecondary cold boxes via a plurality of pipes and then send theliquefaction refrigerant, after being combined, to the first coolingcold box via a first return line.
 21. The liquefaction method as claimedin claim 18, further comprising a second precooling withdrawal lineconfigured to remove the liquefaction refrigeration stream from thefirst cooling cold box.
 22. The liquefaction method as claimed in claim21, further comprising a means for splitting the liquefactionrefrigeration stream, wherein the means for splitting the liquefactionrefrigeration stream are in fluid communication with the secondprecooling withdrawal line.
 23. The liquefaction method as claimed inclaim 17, wherein the feed stream consists essentially of hydrogen.